


Sweet "First" Times

by damnedxfate



Category: Undertale (Video Game)
Genre: "first times", Alternate Universe - Underswap (Undertale), Creampie, Ecto-Breast (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), Fluff and Smut, Fontcest, M/M, Nipple Play, Papyrus is best wing man, Top Sans, Underswap Papyrus (Undertale), Undertale Monsters on the Surface, Universe convergence, bottom stretch, cheesy dates, stonerbros - Freeform
Language: English
Status: Completed
Published: 2019-03-05
Updated: 2019-03-05
Packaged: 2019-11-12 11:56:23
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,440
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18010475
Author URL: https://archiveofourown.org/users/damnedxfate/pseuds/damnedxfate
Summary: It was their one year anniversary and Sans couldn't be happier. He had everything planned, thanks to Papyrus, and hoped that today they would take things to the next level. Stretch was everything to him and he wanted their "first time" to be extra special in every way.





	1. Is it a picnic if we buy the food?

**Author's Note:**

  * For [Luffymarra](https://archiveofourown.org/users/Luffymarra/gifts).



> Commission from Tumblr for dankiawarden/ luffymara

Sans fidgeted nervously, rereading the checklist his brother had kindly made for him. Papyrus was so cool.   
Sans and Stretch, the Papyrus of Underswap, were going steady close to a year now. In fact today was their anniversary and Sans wanted to do something special. He had brain stormed out loud on what to do. Papyrus had found him clutching his skull and muttering on the couch and decided to lend a hand. He had read the dating manual after all.    
  
Most of the ideas were tossed out. They were either too high stress or complicated. The lazy pair would have been exhausted midway through the day from all the activities and interactions. It was a big step in their relationship, obviously since it’s their anniversary, but sometimes bigger wasn’t always better.   
It was concluded that they should do something simple but meaningful.    
  
The pair would travel to their favorite restaurants on foot. Doing some window shopping on the way, maybe buy something or maybe not it was fun to look, and grab their favorite foods before climbing up Mt Ebott for a picnic under the stars.    
There was a meteor shower tonight and the mountain side ledge they had all emerged from had the best vantage point.   
  
That morning Papyrus had roused Sans from bed with playful teasing of, “WAKE UP LAZY BONES! YOU DON’T WANT TO BE LATE FOR YOUR CANOODLING DATE DO YOU?” that had drawn much sputters and a vivid blush from the shorter but older brother and brought the taller but younger brother into loud “NYEH HEH HEHs” at his expense.    
  
Sans had grumbled still flushed and ate his breakfast, dinosaur oatmeal, and sulked his way upstairs to shower and get dressed.   
He still had his customary hoodie set out and shorts but had put some thoughts into his shirt and footwear. Slippers obviously not the best choice for a day on the town much less to hike up a mountain trail.    
His shirt, bought specifically for this day, was a white t-shirt that had a tux printed on the front giving an illusion of formal wear in a casual feel.    
While Sans admired himself in the mirror, Papyrus gave a call from downstairs that he would be leaving for the rest of the day and night before shouting “AUDIBLE WINK” and closing the door behind him. He had set up a playdate/sleepover at Undyne and Alphys’s house which kept all their friends busy including Blue, Stretch’s brother, so they would be completely undisturbed.   
  
Best wing man, 10 out of 10.   
  
Now Sans was just waiting for Stretch to arrive for the date to commence. He really wanted to show his appreciation and dare he say love to the lanky skeleton. Sans hadn’t been around the block by no means but he wasn’t a virgin either. He had tried to find the one so many times in the past. Wanting that someone special which he thought he had found on Toriel but that was a whole ‘nother story.   
Stretch was different though. It was kind of like a fun house mirror. Someone who understood him perfectly. Been through everything he had been through and suffered for it. It was like two puzzle pieces clicking together in a misshapen mess but perfectly complimenting.    
  
Every little thing was so new even if they had each already done the very same thing dozens of times before. Would you believe that they hadn’t even slept together yet? Despite their sometimes suggestive jokes and flirtatious behavior both had acted like blushing teenagers. Took them forever just to hold hands and by the stars their first kiss had left him a boneless mess.    
  
Sans was hoping to make the next step tonight.   
  
Their first time on their first anniversary.   
  
He would cup Stretch’s high cheekbones and lean in for a kiss. Slide the orange hoodie back to reveal pristine bones he could sink his-   
  
“Should I come back another time?”   
  
The new voice startled Sans into teleporting a few feet away his eye strobing. He hadn’t noticed Stretch shortcut in and plop himself on the couch next to him.    
  
Sans took a deep breath and relaxed, slapping on his usual lackadaisical grin. “Nearly scared me out of my skin there buddy”. He slide the checklist into his pocket to hide it.    
  
Stretch shrugged and stretch his legs out with a smile. “Good thing we don’t have any right?” He looked unruffled as usual. Wearing the same orange hoodie, tan cargo pants and ratty sneakers. The only notable difference being a perfectly knotted bow tie, obviously the work of Blue, around his neck. “Ready to go  on our special date Sansy?”   
  
“Yea. Come on got the whole day planned” Like a gentlemen, Sans held out the crook of his arm to a chucking Stretch and short cut them to their first destination.   
  
The Monster Shopping District.    
  
Everything you needed to know about the place was already in the name. Most of the store owners underground had built their businesses in a cluster on the surface. There were even a few human stores dotting the large square.    
On one side stood Grillby’s and the other was Muffet’s. Both of their favorite ‘watering holes’.    
  
Sans led Stretch the long way around. They stopped at each shop to peer inside, occasionally entering to try something on or buy something. Stretch finding a pair of googly eyed sunglasses and Sans a fake pair of glasses with a large plastic nose on the front at the local joke shop. One they frequented often. They wore it the rest of the trip, stopping just long enough to get a ketchup covered order of burg and fries for Sans and some donuts and honey for Stretch. The fire elemental and spider monster already used to the two comedians antics and not batting an eye, or eyes, at their new looks.    
  
Stretch was side eyeing him wondering what was next. It was a nice to window shop and he had thought they were gonna stop to eat at the bar and bakery but Sans had just led him back out. They were actually approaching the end of the street where it broke from civilization to forest terrain. The well walked path winding its way before them up the side of the mountain. It was actually getting kind of late. The sun a smudge on the horizon painted pretty hues or orange, pink and yellow.    
  
“Come on, we’re almost there” Sans cajoled. He wanted to have them set up and relaxed before the first meteor made its path across the night sky.   
  
Stretch snickered and mumbled, “what a way to tell a guy to take a hike” but his long legs overtaking Sans easily enough.   
  
By the time they reached the summit both were breathing heavily and night had fallen. Sans had noodle legged his way over to the ledge and pulled a blanket out of his inventory to spread on the over the floor. He was gentlemen enough to allow Stretch to sit down first before collapsing against him with a wheeze. Never again. Romantic twilight walk be damned.   
  
The food was set out and both nibbled at it making small talk. Once the food was gone they laid back together holding hands and looking up at the stars.   
  
Stretch tightened his grip a minute and relaxed it. “Thank you Sans. Best anniversary ever” Stretch sighed happily, turning to the side so he could nestle himself on to Sans shoulder and neck. Sans pulled Stretch close by the waist.   
  
“It’s not done yet, look.” Sans motioned over them toward the sky. Dazzling balls of light were traveling through the atmosphere in brilliant trails. Stretch’s gasp of awe made Sans swell in pride.    
  
Today had been perfect.   
  
But it wasn’t over yet.


	2. Out in the open

**Summary for the Chapter:**

> The moon and stars as their witness

The meteor shower had come and gone but the two lovers still stayed cuddling under the stars. Hand holding turning into soft caresses over curved hips and nuzzling kisses across an exposed neck. Heavy kissing bruising them just a shade darker over their teeth since there were no lips to cushion them. 

Sans rumbling purr complimented by Stretch’s slightly higher chirr of pleasure.   
The smaller skeleton taking a more dominant and proactive position having rolled the swap Papyrus unto his back for Sans to nestle himself between long supple legs.    
  
Stretch looked amazing framed by the moon above them. He had his arms over his head lightly grasping the picnic blanket, worrying it between his fingers. A honey blush painting his face accompanied by a gently parted jaw, panting for breath. The sight made Sans want to reach down and kiss him more. Steal back the air Stretch was struggling to pull into his heated body.   
A familiar blue jacket was bundled off to the side so Sans could have full range of motion. Which he had capitalized on immediately.   
Mapping out Stretch’s body like the world’s first explorer. Hiking up the orange hoodie to bunch under Stretch’s neck and armpits showing off, funnily enough, an exact replica of the shirt Sans himself had on. They really did think alike.   
  
There was one key difference.   
  
The tuxedo printed shirt was lifted by two glowing, distinctive shapes.. His magic had molded breast from excitement. The aroused nipples, hardened and perked, pointed upward begging for Sans to touch them, roll them between his fingertips and draw them into his warm, wet mouth.    
Which he did. Right over the fabric of the shirt.   
  
“Fuck! Haaah gentle” Stretch whined, sensitive and aroused. Sans had brought his hands up to push the two treasures together. Bringing them just a bit inward so he could rotate his thumbs over the buds before drawing them in with a coil of his tongue.    
“Oh sh-shiiit” long elegant hands, stained from cigarettes and still a bit sticky from their previous meal, clamping on the back of his skull to hold him in place. Tall body squirming indecisively. Trying to both push the breast higher into the pleasure or cant hips upward to seek friction. The soft mound being pushed against Sans’s femur before it bumped and rubbed against his hardened length.   
He graciously lowered himself to bury his clothed cock between the spread legs to give them both the gratification they wanted.   
  
His moan of ecstasy inaudible over Stretch’s shriek of pleasure. The dual sensation of his breast being sucked and the pressure to his swollen nether lips bringing a fresh gush of slick. Together they danced. Rutting on instinct. Ratcheting themselves higher and higher into the precipice of pleasure.    
Both shaking from the exertion. The shirt, now with two wet spots, pushed to bunch up with the hoodie allowing Sans to paw and massage the breast. Bone on soft pseudo flesh until the pressure was too much, just on the border of pain from over sensitivity, making the once caging hands to drag him up forcefully into another bruising kiss.   
  
Blue and honey yellow clashing in a fight for dominance long since decided. Each individual taking the reprieve to shimmy out of their confining pants until bare flesh met with a slap.    
  
Sans cock sliding against a wet vulva to nose forcefully the engorged pearl at the top.    
“Please, Stretch. I love you so, hah, much. Can I?” Sans pleaded. He drew his hips back to line himself up with Stretch’s opening, just barely parting the magic. He wanted this so bad and could feel how much the other wanted it too, but he would stop if Stretch had even the slightest bit of doubt. Sans loved him more than anything in the world. He would never even think of compromising their relationship just to satisfy his urges.    
  
His answer came from all sides. Stretch’s mouth turning into a wide smile and a snort of laughter before long limbs brought him closer. Arms sliding up his lower back to grib his shoulders from behind and long sinewy legs clamping around his waist to cross right above his rear. The only road now being forward.   
  
“Come on, show me a sans-sational time” Stretch said throwing him a coquettish wink, using what he knew to be one of Sans’s favorite puns. They both chortled a moment before sighing. Each with the same sappy love-sick smile. They really were in love. So perfect for each other.   
  
It was under the stars, the very place both began their new, reset free life that they connected for the first time. Sans sliding home in a slow, deep thrust, their hips meeting with a muted thump.   
  
It was amazing. Nothing had ever felt this good and right in their entire lives. Warm, clenching walls, rippling and sucking over hot, thick magic prodding it’s way into every crevice it could. Striking each nerve with electrifying clarity.    
  
Words weren’t needed anymore. Their bodies from then on did all their talking. Bodies undulating rhythmically. Hips pulling back to snap forward with white hot intensity. Stretch’s hand’s clawing across white scapula and blue skin. His legs weak from pleasure widening to jolt freely with each thrust until Sans gathered them each into the crook of his inner arms. Wider and higher to reach deeper. The cock now hitting his most pleasurable spot dead on. The Papyrus was sobbing with pleasure.    
Sans had braced his feet and toes into the blanket. Lifting himself into a half kneeling position to bring more vigor into each inward ramming thrust. Folding Stretch in half to latch onto one jiggling breast. A palm coming up to capture its twin. Clamping the nipple between index and forefinger while he rolled the mass in counterpoint.    
  
Stretch was the first to finish. His body freezing before tightening up around Sans, trapping him in place. To many good sensations. The orgasm coming with startling force bringing a choked “oh” from Stretch before he released a loud whine. His pussy clamping tight over Sans keeping him from moving while his slick juices gushed between them. Finding any available space to drip and stream its way through.   
It was enough to drag Sans over as well with a grunt. Releasing inside the constricting channel in spurts. Overfilling it until his thick seed joined the wet procession between their bodies. Sans gave a few more jerks, milking himself before all but collapsing on top of Stretch. Both desperately panting to cool their sweat and cum slicked bodies.    
  
“Well...damn that’s one hell of a-hah first time...Wanna go for round two?” Stretch huffed, humor in his voice.    
  
They both laughed out loud and short cut away leaving behind a messy and slightly torn blanket for nature to claim. 

**Author's Note:**

> if you enjoyed let me know! please kudos or comment!


End file.
